/*
 * Copyright 2015 GenerallyCloud.com
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */ 
package com.generallycloud.nio.codec.http2.hpack;

import java.io.ByteArrayOutputStream;
import java.io.PrintStream;

import com.generallycloud.nio.common.CloseUtil;

public class ThrowableUtil {

	private ThrowableUtil() {
	}

	/**
	 * Set the {@link StackTraceElement} for the given {@link Throwable}, using
	 * the {@link Class} and method name.
	 */
	public static <T extends Throwable> T unknownStackTrace(T cause, Class<?> clazz, String method) {
		cause.setStackTrace(new StackTraceElement[] { new StackTraceElement(clazz.getName(), method, null, -1) });
		return cause;
	}

	/**
	 * Gets the stack trace from a Throwable as a String.
	 *
	 * @param cause
	 *             the {@link Throwable} to be examined
	 * @return the stack trace as generated by
	 *         {@link Throwable#printStackTrace(java.io.PrintWriter)} method.
	 */
	public static String stackTraceToString(Throwable cause) {
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		PrintStream pout = new PrintStream(out);
		cause.printStackTrace(pout);
		pout.flush();
		try {
			return new String(out.toByteArray());
		} finally {
			CloseUtil.close(pout);
			CloseUtil.close(out);
		}
	}

}
